Roman Coin with an Astronomical mystery discovered off Israel's coast

 

Israeli Antiquities Authority's Marine Archaeology Unit recently found a rare, 1877-year-old bronze coin with the Roman Moon Goddess Luna above a depiction of the zodiac sign Cancer (a crab). The coin was found off the Carmel Beach in Haifa. On the other side of the coin is the head of Roman Emperor Antoninus Pius (131-161 AD) during whose reign it was minted.   In ancient Roman mythology, Luna is the deity representing the moon and she is best known for wearing a crescent as a crown and riding her chariot as she casts the darkness of the night. She is the female counterpart of her brother Sol, the personification of the sun.

                         

Rare bronze coin depicting Cancer the crab beneath the moon goddess Luna

Unit director Jacob Sharvit said, it was the first time such a coin has been found off Israel's coast, and this coin was found among a small hoard of other coins probably from a shipwreck. The coin was minted in Alexandria, Egypt, and is dated ''year eight'', or the eight year of Antoninus Pius's rule, or 144/145 AD. Pius's reign was well remembered, and historians note him as one of the ''Five Good Emperors'' alongside Nerva, Trajan, Hadrian and Marcus Aurelius.                        

The Rare bronze coin depicting Cancer, the crab sign below goddess Luna on one side and Emperor Titus Aelius Hadrianus Antoninus Pius on the other side, bearing the date ''Year eight'' i.e. 144/145 AD

The coin in particular is no exception, with the writing telling us exactly when and where the coin was minted, but the interesting depiction on the coin sent the astronomical community into interesting research. This coin would have been part of a set of twelve, depicting the houses of the zodiac. David Dickinson, in an article published in ''Universe Today", Courtenay, BC, writes that he did begin to wonder if this depicted a real astronomical event, visible from the Mediterranean region in the times when the coin was minted. As no bright star exists in Cancer, he suspected it was actually a bright planet, say, Jupiter or Venus. He used the ''Occult 4.2 program'' and the planetarium program ''Stellarium'' (which takes into account the -26,000-year precession of the equinoxes and stellar proper motion over the centuries) and found one event that was specially intriguing: the dusk conjunction of the waxing crescent Moon and Jupiter on the evening of June 4th, 140 AD, in the sign of Cancer.

                         

Dusk looking west from the Mediterranean region on the evening of June 4th, 140 AD: Credit Stellarium

 

Not only did this occur in the reign of Antoninus Pius, but it would have been visible right before the death of his beloved wife Faustina the elder in 140 AD.  Perhaps the ancient coin commemorates her passing. Certainly, there is record of Pius's devotion to Faustina, and his subsequent campaign to deify her after death.                        

The Moon occults Jupiter, June 4th, 140 AD, Credit: Occult 4.2

Modern Astronomy has its roots in the archaic practice of astrology. Ancients watched the sky, noted what they saw and corelated them with actual events. There are many such examples. We remember the astrologer's admonition to Julius Caesar to beware the Ides of March (15th of March), the day he was brutally murdered. Under one possible scenario, a court astrologer could have assigned significance to the conjunction of Jupiter with the moon in Cancer, a portent that later moved a grieving Pius to commemorate the death of his wife, casting her as the Moon goddess Selene.                       

The base of column of Antoninus Pius in Rome, depicting Pius and Faustina, Credit: Saiko/Wikimedia Commons 

    

There was another interesting possibility for the mystery star. As per John Flannery, it could have been Halley's comet of 141AD. He ran a simulation using data from NASA/JPL/Horizons, and 1P/Halley would have been at Right Ascension 9 hours, 13' 12' Declination+ 24 degrees 10' on April 28th, 141 AD in the adjacent constellation of Leo, the Lion shinning at +1st magnitude while the Moon was in Cancer at dusk.                          

Halley's Comet in late April, 141 AD, Credit: Stellarium

 

In astrology, the Moon rules the sign of Cancer. We may never be very sure what the coin intended to depict, but such depictions on coins are important to try and pinpoint the dates and events of the past   

Antoninus Pius

Universe Today